文档介绍：毕业设计(论文)
题目名称:基于FPGA的OFDM宽带数据通信同步系统设计与实现
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2010 年 6 月
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基于FPGA的OFDM宽带数据
通信同步系统设计与实现
Design and Realize the Synchronization
System for Broad Band
munication Based on FPGA
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摘要
OFDM(正交频分复用)技术作为一种可以有效对抗信号信道间干扰和符号干扰的高速传输技术,引起了广泛关注。它利用许多并行的、传输速率较低的子载波来实现高速率的通信。它的特点是各子载波相互正交,所以扩频调制后的频谱可以相互重叠,不但减小了子载波间的相互干扰,还大大提高了频谱利用率。由于具有高频谱利用率、易于硬件实现、对抗频率选择性衰落和窄带干扰的能力突出等优点,它成为第四代移动通信的首选技术,也是当前移动通信技术研究的热点问题。
本文概括的介绍了OFDM系统的基本概念、基本工作原理和关键技术以及OFDM通信系统的组成,详细分析了各种同步误差的引入以及各种误差对于系统的影响。
同步技术是OFDM系统最关键的技术之一,它包括载波频率同步和符号同步等。载波频率同步是为了纠正接收端相对于发送端的载波频率偏移,以保证子载波间的正交性,符号同步确定符号有用数据信息的开始时刻,也就是确定FFT的开始时刻。本文设计了一种理想的OFDM系统,包括串并转换、星座映射、调制解调等,并且介绍了一种基于自相关的符号同步算法,在对算法作理论研究的基础上,给出了它的基于FPGA的实现方案。
关键词:正交频分复用(OFDM),现场可编程门阵列(FPGA),符号同步
Abstract
OFDM (orthogonal frequency division multiplexing) is a high-speed transaction technology, which can defeat ICI(Inter-Channel Interface)and ISI(inter-symbol interface),so it makes OFDM more and more transmits high-speed data through many sub-carriers which are parallel and have lower transmission the sub-carriers are orthogonal ,so their frequency spectrum can be lapped from each can not only decreases ISI ,but also increases the frequency spectrum utilization. Because all of above, OFDM has been the first choice in 4G munication technology.
In this paper, the basic theory, fundamental operating principles, key technology and the munication ponents, have been inteoduced. At the same time, the effects of synchronization error to the system are analyzed in detail.
As one of the most crucial technique of OFDM, synchronization technique includes carrier frequency and symbol frequency synchronization rectifies the carrier frequency offset between transmitter and receiver, ensuring the orthogonality among sub-carriers, and symbol synchronization determinates the beginning of useful data in an OFDM symbol, which is also